Your diagram did not show; if it is an image stored in a Google account, I don't think it will show up here properly.  You can download onto your computer, and then upload it here.

In any case, to answer your question, let's try to find the point on the given diagram that represents the case where Jack arrived at 5:16, and Jill arrived at 5:46. By the description of the question, Jack waited till 5:45 and then left, so they didn't meet.  In the diagram, each point represents the arrival times of these two people.  The coordinate corresponding to Jack's arrival time is the $y$ direction at $16/60$, and for Jill's arrival time it is the $x$ direction at $46/60$.  This point is outside the shaded region.